Parametric analysis for nanolubricant in vapor compression refrigeration cycle

Abstract

With the escalating global energy crisis and the consequential surge in energy consumption, particularly attributed to air conditioning (AC) systems in buildings, there arises a pressing need for sustainable solutions to mitigate this escalating demand. Vapor compression refrigeration (VCR) cycles, ubiquitous across residential, commercial, and industrial sectors, represent a significant portion of global electricity consumption, exceeding 10%. This demand is further exacerbated in regions characterized by hot climates. Consequently, there is a critical imperative to address the environmental impact of these systems, particularly in terms of reducing their Global Warming Potential (GWP). In response to this imperative, this study aims to develop a comprehensive numerical model for VCR systems, focusing on the implementation of nanolubricants. The primary objective is to assess the impact of integrating Al2O3 nanoparticles into the lubricating oil (referred to as nanolubricant) on the performance of the VCR cycle. The scope of the study encompasses the investigation of nanolubricants within refrigeration systems, aiming to enhance their efficiency and environmental sustainability. Utilizing the Engineering Equation Solver (EES), a numerical model of a VCR cycle utilizing R-410A refrigerant is developed. The model specifically emphasizes the compressor component, which is flooded with a polyolester (POE) oil base. The study explores various parameters, including ambient conditions, refrigerant-to-oil dissolving ratio, and mass concentration of nanoparticles, to evaluate their influence on system performance. The results indicate a significant enhancement in performance when flooding the base oil before introducing Al2O3 nanoparticles, with further improvements observed upon nanoparticle integration. Specifically, the coefficient of performance (COP) of the VCR system exhibits a notable increase compared to the base case configuration. Additionally, the adoption of eco-friendly refrigerants, such as R-32, demonstrates promising COP values following nanoparticle implementation by up to 4%. Moreover, the study reveals a reduction in compressor discharge temperature by up to 20% with higher oil mass concentrations during nanolubricant implementation, indicating enhanced durability and longevity of the VCR system’s compressor. These findings underscore the potential of nanolubricants to contribute to both the efficiency and environmental sustainability of refrigeration systems. In conclusion, the findings of this study offer valuable insights into the utilization of nanolubricants in VCR cycles, highlighting their potential to enhance system performance and mitigate environmental impact. These advancements hold promise for the development of more sustainable refrigeration technologies in the face of mounting energy challenges.